Final answer:
Scatter advertising is the purchase of television advertising slots by national advertisers without specific time periods or programs, allowing for a broader reach. Local stations broadcasting national network programming are called affiliates, and television as a medium has evolved to offer targeted advertising through specialized cable channels.
Step-by-step explanation:
All non-network television advertising by a national advertiser is known as scatter advertising. Scatter advertising refers to the purchase of advertising slots on television without committing to specific programs or time periods in advance. This contrasts with up-front advertising, where advertisers buy spots for a specific show or time well ahead of the television season. Scatter ads can be aired during various programs and times, allowing advertisers to target their messages more broadly or to fill gaps in their advertising schedule.
A local station that broadcasts national network programming is called an affiliate. These affiliates are crucial for national networks as they distribute the programming to local viewers. Over the decades, television advertising has evolved significantly, with the traditional major networks being challenged by the advent of cable TV, which offers more specialized channels and thus more targeted advertising opportunities such as on channels like CSPAN and ESPN. Television remains a powerful medium for advertisers due to its vast reach and the ability to collect sophisticated viewer data to target ads effectively.